Lithographic printing.



J. C. HOUSTON.

LITHOGRAPHIC PRINTING.

APPLICATION FILED NOV. 15. 1915.

1,185,506. v Patented May30,1916.

Jesse [locale/z I Cutaway v JESSE C. HOUSTON, OF WASHINGTON, DISTRICT OF COLUMBIA.

LITHOGRAPTHIC PRINTING.

To all whom it may concern:

Be it known that I, Jesse C. HOUSTON, a citizen of the United States of America, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Lithographic Printing, of which the following is a. specification.

This invention relates to lithographic printing and has for its object to provide a process for transferring an image such as an illustration, drawing, etc., directly without the use of a negative or copy on transfer paper as is now the practice to the surface of a prepared metallic plate, or any other plate or stone used in lithographic work, and then fixing the image on the plate in such a manner that ink may be applied thereto and innumerable copies of the original obtained by pressin upon the plate or the plate upon sheets of ordinary paper in the usual manner.

'I have illustrated in the accompanying. drawing several views sliowing the different steps by which my process is carried out and various paraphernalia incidental thereto in which drawings:

Figure 1 is a diagrammatic perspective view of a light translucent or transparent paper having a drawing inscribed upon its surface. Fig. 2 is a view of the plate after i its exposure to actinic light and covered with anilin dye. Fig. 3 is a similar view of the plate after development.

In lithographic processes heretofore emf ployed, it has been necessary to first make a} negative, then to make a print of this negative upon sensitized transfer paper, and finally retransfer the image from the transfer paper to a' lithographic stone. When it is desired to make large lithographic prints containing much detail by the aforesaid process, it.

becomes necessary to make the print in sections because 'of the fact that a large glass negative the same size of the print desired'is expensive and difficult to handlefand therefore a number of glass negatives are made of sections of the original image and .then transferred to a stone. Withline designs a tracing is made and used in the transfer.

Each case entails considerable work and opens up opportunity for errors to arise in many ways and consumes much time.

My process enables me to obyiiate the above disadvantages because Ido not use a negative tracing or copy on transfer paper to transfer'the original to the lithographic;

Specification of Letters Patent.

Application filed November 15, 1915. Serial No. 61,677.

Patented May '30, 1916.

stone or plate. As metallic plates are obtainable of any size-at a comparatively small cost, these features are of obvious advantages and, furthermore, the imageis fixed upon this plate which becomes'an impression plate, the only remaining stepsnecessaryare to ink this plate and to impress upon it ordinary paper to obtain duplicate copies of the original. My/process therefore is of inestimable value when making copies of large map drawings, machine drawings or the like.

In carrying out my invention to the best advantage, it is preferable that the original' drawing be upon some translucent or transparent substance such as tracing paper, linen,'or the like, designated 1 in the drawing. A metallic plate, usually zinc, designated 2, but other metals such as aluminum, copper or tin may be employed, is prepared by flowing over'it a sensitized solution prepared according to the following formula. -I havefound the following formula to give excellent results, but it is understood that changes of proportion 'Of the ingredients may be made without departing from the spirit of my invention. 2 ounces clarified 'glue (preferably Le Pages), ounce ammonium bichromate, 16 ounces water, ounce splrits' of ammoma.

A suitable coating of the solution is placed; upon the plate and dried. The original 7 v drawing is then superposed upon the plate now sensitized, and the whole exposed to actinic light in a suitable frame. The time for exposure to obtain theimage is best determined by experiment for it is" effected by both; the quality of light and the light transmitting property of the material upon which the original has been drawn or placed and a visual examination of the plate to note progress of the printing-isnot entirelydependable in view of a later developing process required, which brings out the images more clearly. The chief object of this exposure is to create a condition upon the plate whereby llthographlc' inkwill be caused tobecome adhered to certain portions-of the plate and expelled at others.

After the plate-is sufiiciently exposed it is placed in a developing bath prepared as follows; '1 ounce anilin dye, 16 ounces water. Any colored dye may be used which is soluble in water. a The effect of this development is to cause those portions of the sensitized surface of the plate which have been exposed to light to absorb the coloring matter of the -devel-' oper, and as a consequencethose portions of the sensitized surface which'have been hid- .den from the light beneath the lines of the drawing will be sharply defined because of the washing away 0 After this development; the plate is dried' the unaffected glue.

and a solution poured over its surface, which solution is prepared as follows: 1 lb. of best asphaltum, 4 ounces of 'whitebeeswax', and 4 ounces of mutton tallow,- heated and melted together, and while this mixture is still hot the following ingredients are added: 5 pints of turpentine,-1 ounce of oil of lavender, and ounce of terpene, and the whole thoroughly mixed. After the plate is'coated with the asphaltum mixture and dried, it is placed in a bath made up of 1 ounce hydro-. chlor ic acid, and ounces water.: As a result of this treatment the anilin tinted surfaces of the developedplate will be washed free of color and the'asphaltum filled lines of the plate sharply. defined. The plate-isnow ready for printing, whi'chis accom-' .plished by applying lithograph ink to the plate by means of a roller and then laying a; sheet of ordinary paper down upon the plate desired to carry. fut my process in con- HGCtlOIl with ofi'set printing,- the print is; made positive on the plate and is then trans and applying pressure in. the usual press:

The effect upon the ink when applied to the plate is -to become adhered; to the asphaltu n filled lines and'to become expelled from surfaces not coated with asphaltum, thereby giving a positiveprint in facsimile of the original drawings. Of course it will be understood that. ifit ferred to a blanket "or. thelike, from which duplicates can be .made in the u'sualmanner.

Thusit'will be seen that I have disclosed a process for obtainingia plate adapted for printing a positive copy from an original drawing or design-without the intervening preparation of a negative or the transfer of a print to; an impression surface;

It is to be further understood that while I have given specific directionsforfcarrying out my' processk-andhave specified certain I materials-I do not wish to. limit myself to the exact means described, but I wish toobtain the benefit of all modifications of the -ajbovedescribed process without departing I claimis:

. LA process for preparing plates for from the spirit'of my inventionor the scope. of the appended claims.

-Having thus desc ed my invention what printing .which consists in exposing a metallic sensitized plate under a translucid medium' containin the original'image, treating the plate wit a chemical which will cause. the exposed part'thereof to become repellent to'agreasy substance, treating the plate with the image.

a greasy substance and washing said plate to' remove the unexposed sensitive medium, whereby ink will adhere only to the unexposed portions defined by the image.

2. A process for preparing plates for i 3. A process printing which consists in exposing a metallic plate sensitized withglue and ammonium bichromate under a ytranslucid drawing,

treating the plate in a solution containing 'anilin dye which will cause the exposed part thereof to become repellent to a greasy substance, washing the plate, applying a "easy substance to the. plate, and then for preparing plates for v washii g the plate in diluted hydrochloric acid, whereby ink will adhere only to the unexposed portions defined'by the image.

' 4. A process for developing bichromated plates used for an. impression printing surface, which' plate has been previously exposed under a transluciddrawing or the like, consisting in. treating the exposed plate with a solution of anilin dye, further treating the plate to cause ink to adhere only to the unexposed portidns, then washing the. plate in diluted hydrochloric acid.

5, A process for preparing plates to be used for-lithograph printing which consists in" developing a sensitized plate which has been exposed beneath a transparent drawing or the like whereby the lines of the drawing.

are defined on the plate and treating the plate with. anilin dye and then with greasy material, whereby the lines become filled with saidmaterial and ofier a surface adapted to absorb ink.

6. A process for preparing plates to be used for lithograph printing which consists in coating said plates with a sensitizing solution made of glue, ammonium bichromate, water and spirits of ammonia, and exposing same, then developing said plate in a developing dye solution and subsequently subjecting the plate to a line filling material made of greasy. substance, and finally washing the -,plate in a developer remover containing acid.

7, A'process for preparing plates to be j used for lithograph printing which consists in coating said plates with a. sensitizing solu tion includin ichromated colloid, then exposingthe p ate and developing the plate in -a'solution of anilin dye and water, and subsequently treating the plate with 'a line filling material composed of greasy substance, and finally washingthe plate in a a developer remover containing acid.-

8. A process for preparing plates to be used for lithograph printing which consists in coating said plates with a solution. exposing the finally Washing the plate with a developerrenriover containing acid.

9. A process for preparing plates to be used for lithograph printing which consists in coating said plates with a solution containing sensitized glue, exposing the plate,

then subjecting the plates after exposure to a developing dye solution, then treating the plate to a line filling material made of greasy substance, and finally washing the plate in a developer remover of hydrochloric acid and water. v

10. A process for preparing plates to be used for lithograph printing which consists 25 in coating said plate with a sensitized colloid solution, subjecting the plate after exposure to a developing dye solution, subsequently treating the developed plate to a solution composed of sixteen parts of asphaltum,

four parts of beeswax, four parts of mutton tallow, sixty parts of turpentine, two parts of oil, and one part ofterpene.

In testimony whereof I aflix my signaturein the presence of two witnesses.

JESSE C. HOUSTON. \Vitnesses:

J. M. IMIRIE, F. M. Marne. 

